Intermittent film feed mechanism



Sept., 7, 1948.' R. A. cLAPP 2,448,519

IHTERIITTENT FILM FEED MECHANISH ai@ 4,5 Invenkdr:

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Sept. 7, 1948. R. A. cLAPP INTERMITTENT FILM FEED IIECHANISM 2 Sheets-Sheet 2 Filed Ju1yl9, 1944 mm. w TT z M Tw mw .zmnum- -T I :Wil WJ.. .M .L

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Patented Sept. 7, 1948 IN TERMITTENT FILM FEED MECHANISM Roy A. Clapp, Minneapolis, Minn., assigner, by mesne assignments, to Argus, Incorporated, Ann Arbor, Mich., a corporation of Michigan Application July 19, 1944. serial Nq. 545,624

' a emma. (ci. ss,1s.4)

This invention relates to motion picture projecting apparatus wherein an evenly perforated film bearing evenly spaced image frames thereon is progressed through -a projector apparatus in a step-by-step motion for the projection of the image frames. For the purpose of advancing the film step-by-step, the projector apparatus includes a film guide and in prior mechanisms of this type the film guides have been subject to breakage and excessive wear due to the relatively close spacing of the light aperture and slots therein, which, as heretofore made, have tended to weaken the film guide.

It is an object of the present invention to provide an improved projecting apparatus andparticularly to provide an improved lm guide or raceway. It is a further object of the invention to provide a projecting apparatus including a novel means for advancing the film and an improved raceway film guide of rugged design capable of withstanding long usage and wear. It is a further object of the invention to provide a film guide raceway wherein the light aperture and slots, through which the film perforations are engaged, are widely spaced so that the raceway is not unduly weakened. It is also an object of the invention to provide as an article of manufacture an improved film guide raceway of rugged construction.

It is also an object of thev invention to provide a film moving mechanism capable of progressing view, partly in section, of a motion picture film and apparatus for progressing the same;

Figure 2 is a -plan view. partly in section, taken along the line 2-2 of Figure 1;

Figures 3 and 4 are enlarged fragmentary front elevational views of the raceway of a film therein and the film progressing mechanism;

Figure 5 is a fragmentary side elevational view of a portion of the film feeding mechanism;

Figure 6 is an enlarged fragmentary view taken on line B-S of Figure 9 of the film guide raceway showing the clamping plateremoved;

Figure '7 'is a side view in section of a portion of the projector apparatus showing the film guide raceway and clamping plate and a portion of the lens mounting;

Figure 8 is a front elevational view of the film guide raceway removed from the remaining portions of the apparatus;

Figure 9 is an enlarged plan sectional view taken along the line 9 9 of Figure 6;"

Figure 10 is a fragmentary sectional view taken along the line ill-i0 of Figure 6:

Figure 1l is a front elevational view of the film removed from the raceway; and

Figure 12 is a front view of the lm'guide presf sure plate.

-parallel arms i4 and i5, the latter serving as mountings for the pivot screws I8 and I1 which are threaded through the arms I4 and I5, respectively. The pivot screws support an oscillating frame generally designated 20 having upper and lower flange frame pieces 2i and 22, front and rear frame bars 23 `and 2l. 'I'he pivot screws i6 and I1 project into bearing blocks 26 and 21 and the frame 2li is therefore free to move in an oscillating motion back and forth as indicated by the arrows 28 and 29. The frame 20 is normally urged in the direction of arrow 28 by a U- shaped spring generally designated 30 `having a bar piece 3i which is in contact with the side arms 33 and 34 of the frame piece 24. The spring extends around the headed posts 36 and 31 and the ends 39 and 40 are extended through apertures in the machine frame I0. The frame also includes a cam rider 4i which serves to oscillate the frame, as hereinafter described.

Upon the frame there are pivoted two arms 42 and 43, the arm 42 being pivoted at 44 to the side arm 33 of the frame Vand the arm 44 being pivoted at 45 to the side arm 34 of the frame. The arms extend in a direction parallel to the frame and are tied together'at their extreme left end. as shown in Figure 1, by means of a link 4l which is pivoted to the arms at 48 and 49, as indicated in Figure 5. The link is provided ywith bent over .claws 5i and 52 which are spaced apart so as to engage widely separated apertures I and 5 of the pairs of apertures in the lm generally designated 55. The film moves through the race- 3 way generally designated 56 which is of a configuration hereinafter described. The arm 42 is provided with a cam rider 54 and arm 43 is provided with a cam rider 53. The cam riders 53 and 54 are arranged to ride upon a cam surface 59 which is on shaft 60. The shaft 60 is driven by gear 6| and is rotatably supported in bearing blocks 62 and 63, the latter in turn being supported by frame members 64 and 65 attached tothe machine frame generally designated I0.

The shaft 60 is also provided with a cam generally designated 61 which has a cam surface 68 upon which the cam follower 4| of the swing frame 20 is adapted to ride. 'I'he cam 61 is shaped so -as to oscillate the swing frame 20 back and forth in the direction of arrows 28 and 29, oneoscillation for each revolution of the shaft 60, and since the arms 42 and 43 are attached to the frame, the opposite end of the arms and the link 41, having claws 5| and 52 thereon, are all likewise moved in an oscillatory motion from a position out of engagement with the film perforatlons, to a position in engagement with the film perforations. The swing frame also includes a flat retaining member 32 which serves likewise to hold the arms 42 and 43 against the member 23 of the swing frame, the arms being free to slide vertically with reference to the swing frame.

The cam 59 which is also mounted so as to rotate with shaft 60 is shaped so as to impart to the cam followers 53r and 54, and hence to the arms 43 and 42, a vertical oscillatory motion in timed relation to the motion produced by cam 61. The extent of the vertical oscillatory motion of the arms 42 and 43 is suficient to move the claws 5| and 52 a distance equal to the spacing between successive image frames on the film, plus a slight distance in addition, so that as the claws 5| and 52 are moved toward the film the leading claw (in the direction of lm movement) will slightly clear the edge of the perforation. The trailing claw clears the edge of the perforation by a substantial distance, as hereinafter explained.

The details of the film progressing mechanism illustrated in Figures 1 and 2 form no part of the present invention and are more specifically described and claimed in my application entitled I Tape movingmechanism, Ser. No. 545,626, filed .,M'ofeven date herewith, now United States Letters Patent No. 2,409,834 issued October 22, 1946,

which'is 'incorporated herein by reference. For

the purpose of the present invention the entire film progressing mechanism may be substituted by fi vv,any film progressing-mechanism capable of ad- 'cing the film in a step-by-step motion a dis- ,l "tanceequal` to the spacing between successive film frames, provided the film engaging claws are l spaced apart a distance greater than adjacent film perforations, and spaced one above and one below theA light aperture. Thus the film progressing mechanism shown opposite the bracket of Figures 1 and 2 may be substituted by any other suitable mechanism.

Referring to Figures 1-5 it will be observed that the `film 55 is provided with a plurality of successive image frames A, B, C, D, E and F and a plurality of film perforations I, 2, 3, 4, 5 and 6, there being one perforation for each frame at the line between successive frames. It is to be understood, of course, that any system of perforation, Whether at the lines separating the frames or otherwise, may be used. 'I'he usual film perforation is as illustrated herein. The lm is guided by a guide generally designated 56 and is moved by the film progressing mechanism heretofore described due to the engagement of the claws 5| and 52 with apertures in the film.

It is a feature of the present invention that the selected perforations for progressing the film are spaced from each other more remotely than adjacent perforations. Thus, it will be observed that the claw-52 intercepts perforation i of any series of perforations, whereas claw 5| comes into the perforation 5 of said series. 'Ihe claws 5| and 52 are spaced from each other a distance such that when claw 52 is in engagement with the marginal wall of perforation claw 5| is located centrally within perforation 5. As illustrated in Figures 3 and 4 the claws 5| and 52 are spaced apart a distance greater than the center to center distance between the engaged perforations and the dimension of each claw in the direction of film movement is suiciently less than the corresponding dimension of the associated perforation that both claws clear the film at the perforations when entering 'the latter. This is provided so that the film is drawn, rather than pushed, through the machine, the direction of normal film motion being downward, as illustrated by the arrow 1| of Figure 3. It occasionally happens that one or more film perforations may be torn out and in the usual film projecting apparatus this causes a stoppage of the film which can only be cleared by the operator opening the machine and progressing the film by hand a few frames and thereafter starting the machine. In the present apparatus the tearing out of as many as four perforations does not cause any stoppage of the film feed because in the event perforation 2, for example, should be torn out claw 52 in its oscillatory motion immediately following that shown in Figure 3, would not therefore engage perforation 2 which is assumed to be torn out and in this event claw 5| would engage perforation 6 and would push the film through the film guide raceway for as many frames. as may be necessary to clear the torn'perforations.

It is occasionally desirable, particularly in the projection of educational moving pictures to reverse the direction of film through the machine in order to permit a re-run of a selected portion of the'film. For this purpose reverse running the film feeding mechanism of the present invention,

having claws spaced apart a distance greaterl than adjacent apertures, permits a. feed as illustrated in Figure 4 wherein the film is reversed as indicated by the direction of arrow 12. In Figure 4 the film 55 is about to be moved upwardly in the reverse direction, indicated by arrow 12 by the engagement of claw 5| with aperture 5 and in this instance claw 52 idles centrally within aperture In Figures 3 and 4 the projection station is indi-cated by the dotted lines 14 which indicate the outline of the framing mask utilized in the projector.

Referring to Figures 6-10 there is illustrated the raceway for guiding the film. The raceway generally designated is provided with smoothly curved ends 8l and 82 terminating in fiat pieces 83 and 84 which are attached by suitable screws 85 and 86 to a portion of the machine frame |0. The raceway is preferably of stamped metal, although it may be machined or cast. and includes marginal side flats 81 and 88. as illustrated in Figures 9 and 10. The marginal edges of the flats lie in contact with suitable grooves 89 and 90 in the frane i0. Between the marginal fiats 81 and B8 there is a recessed portion defined by walls 92 and 93. the recessed level being at 94. The fiat area 94 has a width as indicated by bracket 95 5 and is coextensive with the edge of the film bearing the iilm perforations. Between wall 92 and the opposite edge of the flat portion 94 there is a further recessed portion 96 having a width as indicated by the bracket 91, this portion being coextensive with the nlm frames or of slightly greater width. A beading longitudinally of the film guide raceway is provided at 98 andhas a level equal to that of the iiat portion 94 and serves to support the film between the image frame and the sound track. Adjacent the beading 98 there is a further depressed area 99 indicated opposite the bracket and there is provided a narrow marginal fiat area |02 -upon which the edge of the film adjacent the sound track slides. The disf tance between walls 92 and 93 is just slightly greater than the width of the nlm used in the apparatus and wall 93 is cut away at apertures and |06 so as to permit the ends |01 and |08 of the spring |09 to ride against the edge of the film and thus force the film into sliding engagement with the opposite side wall 92 of the race- Way. The spring 92 issupported by screws il!) on the frame member I0, as illustrated in Figures 6 and 10.

It will thus be observed that the film 55 slides in the raceway with its left edge, as illustrated .in the drawings, in contact with the wall 92, urged there by the action of the tips of spring |01 which bear against the right edge of the film. The film does not contact the raceway except throughout the area indicated by the bracket 95, viz. the strip on which the lm perf orations occur together with a slight clearance on each side and along a narrow strip defined by the beading 98 andralong a narrow edge dened by the fiat |02 adj acent wall93. Thus, the sound track, opposite the bracket I0 and the strip occupied by the film frames, indicated opposite the bracket 91, are not engaged by the raceway. The raceway depressions and beadings are blended off into the curves 8| and 82 at the end of the raceway and the iilm reaches the raceway more or lessfstraight and out of engagement therewith. l y

\ Aside from the apertures |05 and |06 the raceway is provided with a light aperture |2 which is somewhat larger than the film frame being projected, inasmuch as the usual framingmask is provided. What is most important the racewair is provided With slots ||4 and ||5 which are removed longitudinally of the raceway, one above and one below the light aperture 2 and consequently there is no thin metal strip at I6 as is found in the usual film guide raceway. In the usual apparatus a slot is provided as indicated by the dotted line ||1 (Figure 8) for passage into the raceway of the film feeding claw of the mechanism, and as a result there is a narrow metal bridge ||6 (Figure 8) between the slot ||1 and a light aperture I2. This seriously weakens the raceway and contributes to the wear of the raceway and the film4 moved through it. By utilizing a film feeding mechanism wherein the film feeding claws are spaced apart a greater distance than adjacent perforations and in which there are no claws to engage the perforations between such` spaced apart perforations, it is possible to dispense with the raceway weakening slot |'|1. The positioning of slots ill and H5, well above the iight aperture ||2, permits a sufficient amount of metal between them so that the raceway is not seriously weakened.

The film 55 is maintained in the raceway -by means of a pressureplate generally designated which is supporte@ 9.1i the lens block generally .der very light pressure.

sure plate |20, with springs |26 removed, is illusdesignated |2| (Figure 7) The lens block is provided with a flange |22 having holes at |23 in which slide a -pair of pins |24 that are solidly mounted on the back of the pressure plate. A pair of very light springs |28 are provided between thel lens block flange |22 and t-he pressure plate |20 so as to urge the pressure plate against the film un- The front of the prestrated in Figure 12 and it includes a light aperture |,|2, a pair of cut-outs |05' and |00 to permit clearance for tips |01 and |09 of spring |09 anda pair of slotsjlll' and IIB' which are arranged so as lto overlie the slots Y| Il and. Il of i the film guide raceway. The pressure plate is provided with outwardly curved ends I 21'|2 1 and between the ends is shaped as indicated in v Figure 10. Thus, it includes a flat surface opposite the bracket 95', a recessed area opposite the bracket 91', a longitudinal bead 98 and ay narrow longitudinal recess opposite the bracket |0|' and a marginal fiat |02'. The shape of this part of the pressure plate is the enantiomorphic image of the shape of the film guide raceway as indicated by the cross sectional views of these parts shown in Figures 9 and 10-.

As many apparently widely different embodi ments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that I do not limit myself to the specific embodiments herein except as defined by the -appended claims.

What I claim is: 1. Apparatus for intermittently feeding a nlm having a succession of indicia bearing frames and a cooperating longitudinal series of equally spaced similar feed perforations past an exposure aperture comprising a claw feed mechanism -having two lxedly spaced claws adapted to be disposed in non-adjacent perforations respectively above and below said exposure aperture when moving the film, and means for actuating said mechanism to successively insert said claws into tance slightly greater than the center to center distance between the engaged perforations, so that during the norma] iilm advancing stroke of said mechanism the leading claw is in contact with the leading edge of its associated perforation to thereby pull the film positively past said exposure aperture and the trailing claw is free of contact with the leading edge of its associated perforation and so that when the claws are moved into engagement with the film to start each cycle of lm feed the leading claw will slightly clear the leading edge of its associated perforation, and each of said claws having its dimension longitudinally of the film sufficiently less than the correspondingv dimension of each perforation that 'both of said claws will clear the trailing edges of said associated perforations when moved into engagement with the film.

2. Apparatus for reversibly intermittently feeding a film strip having a succession of indicia bearing framesv and a cooperating longitudinal series of equally spaced similar feed ,perforations' past an exposure aperture comprising a claw feed 7 mechanism having two nxedly spaced claws adapted to be disposed in non-adjacent perforations respectively above and below said exposure aperture when moving the nlm, and means for actuating said mechanism to successively, insert said claws into said perforations, shift said claws in the desired direction of nlm movement for a distance slightly more than the longitudinal dimansion of one of said frames, withdraw said claws from the nlm and then shift said claws in the opposite longitudinal direction to return them to starting position, the leading edges of said claws being spaced apart in thedirection of movement of the nlm a distance slightly greater than the center to center distance between the engaged perforations, so that during the normal nlm advancing stroke of said mechanism in either direction the leading claw is in contact with the leading edge of its associated perforation to thereby pull the nlm positively past said exposure aperture and the trailing claw is free of contact with the leading edge of its associated perforation and so that when the claws are moved into engagement with the nlm to start each cycle of nlm feed the leading claw will clear the leading edge of its associated perforation, and each of said claws having its dimension longitudinally of the nlm sunlciently less than the corresponding dimension of each perforation that both of said claws wi11- clear the trailing ,edges of said associated perforations when the claws are moved f into engagement with the nlm.

ROY A. CLAPP.

REFERENCES CITED The following references are of record in the nle of this patent:

UNITED STATES PATENTS Number Name Date 1,357,983 Hunt Nov. 9. 1920 1,473,465 Clark Nov. 6, 1923 1,780,945 Sapier Nov. 11, 1930 1,825,254 Victor Sept. 29, 1931 1,828,768 Dina Oct. 27, 1931 1,918,569 Sapiro July 18, 1933 2,106,115 Debrie Jan. 18, 1938 2,168,941 Marks Aug. 8,1939 2,281,726 Stechbart May 5. 1942 2,361,291 Howell Oct. 24, 1944 FOREIGN PATENTS Number Country Date 319,644 Great Britain Sept. 25, 1929 7,003 Australia Apr. 18, 1932 340,340 Germany Sept. 8, 1921 

